1. Field of the Invention
The present invention relates to a disc apparatus, disc recording method, disc playback method, recording medium, and program. In particular, the present invention relates to a disc apparatus, disc recording method, disc playback method, recording medium, and program, for enabling an easy access to a frame which is played back at a frame rate different from that of recording.
2. Description of the Related Art
The frame rate of a video signal in the NTSC scheme is 30 frames/sec, whereas the frame rate of a cinema film is 24 frames/sec.
Pictures having a frame rate of 30 frames/sec and pictures having a frame rate of 24 frames/sec may be edited so as to be combined, and the obtained pictures may be recorded on a disc as a piece of video data (for example, see Patent Document 1: Japanese Unexamined Patent Application Publication No. 9-168148).
When video data including pictures of a frame rate of 30 frames/sec and pictures of a frame rate of 24 frames/sec is recorded on a disc and when the video data is played back from the disc, a playback apparatus plays back the video data at a frame rate of 30 frames/sec, because the NTSC format is used as the standard in this country.
If pictures of a frame rate of 24 frames/sec are played back at a frame rate of 30 frames/sec, the pictures are fast-forwarded because the pictures of 24 frames, which should be played back for 1 second, are played back for 24/30 seconds. Therefore, a so-called 3-2 pull-down processing for converting the pictures of 24 frames/sec to pictures of 30 frames/sec is performed.
Normally, a user recognizes that pictures are played back at a frame rate of 30 frames/sec. Therefore, when the user specifies a frame number so as to search for a predetermined frame, he/she specifies a frame to be searched for while regarding that the number of displayed frames corresponds to frame numbers.
For example, the user specifies a frame No. 100. In this case, if the number of frames of pictures recorded on a disc is counted and if a picture having a frame rate of 24 frames/sec exists among the frames No. 1 to No. 100, the frame number which is actually displayed is smaller than 100. As a result, a frame having the number specified by the user cannot be searched for.